Qld police guess speeds for fines: Stewart

Commissioner Ian Stewart says Queensland Police regularly estimate drivers' speeds before issuing speeding fines.

But if they get it wrong, he says the court system will ensure tickets are revoked.

Asked if Queensland officers write out tickets based on their estimations, Mr Stewart replied: "Absolutely."

But he stressed "estimation" didn't mean officers were simply plucking figures out of the heads.

Rather, they would track a driver they think may be speeding and compare the pace to highly accurate speedometers in police vehicles.

"Not every vehicle is fitted with a radar," Mr Stewart said.

These electronic speedometers meant officers weren't merely guessing - which would never stand up in court anyway, he said.

"If the magistrate's not satisfied, then they'll throw it out," he said.

"I've seen it happen - it happened to me."

The commissioner's admission comes after a truck driver in NSW was pulled over on the Newell Highway for speeding based on an officer's estimation.

"You can't show me the radar?" the driver asks.

"I don't need to. Everything is based on my estimations," the officer replies.

He filmed and uploaded the clip to Facebook, and it's since been watched more than 1.5 million times.